How did Mary Ann Nichols became known as Polly?

Answer 1

It is a little known fact, but the name "Polly" is a variant of the name "Mary". The combinations "Mary Ann", or "Marianne", or "Pollyanna", etc., are common because St. Anne was the mother of the Blessed Virgin Mary: "Mary Ann" simply means "Mary, daughter of Anne". "Polly" is derived from "Molly", which is another form of "Mary". The consonant changes are not unusual for baby-talk, or the Celtic languages (the original languages of the British Isles). That is why Mary Ann Nichols, the first Jack the Ripper victim, was also known as Polly Nichols. Molly fell into disuse because a Moll was a prostitute. Also the p replaces m in other nicknames like Peg for Meg (Margaret)